MAX6660EVKIT Maxim Integrated Products, MAX6660EVKIT Datasheet - Page 20

• Manufacturer Part Number: MAX6660EVKIT
• Description: EVAL KIT FOR MAX6660
• Manufacturer: Maxim Integrated Products

Specifications of MAX6660EVKIT

• Sensor Type: Temperature, Fan Controller
• Sensing Range: -40°C ~ 125°C
• Interface: SMBus (2-Wire/I²C)
• Sensitivity: ±1°C
• Voltage - Supply: 3 V ~ 5.5 V
• Embedded: No
• Utilized Ic / Part: MAX6660
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Remote-Junction Temperature-Controlled
Fan-Speed Regulator with SMBus Interface
the nature of the tachometer output (open collector,
totem pole) and the resultant levels and configure the
connection to the MAX6660. For a fan with an open
drain/collector output, a pullup resistor of typically 5kΩ
must be connected between FAN and VFAN. Note how
many pulses per revolution are generated by the
tachometer output (this varies from model to model and
among manufacturers, though two pulses per revolu-
tion is the most common). Table 14 lists the representa-
tive fan manufacturers and the model they make
available with tachometer outputs.
Table 14. Fan Manufacturers
20
Comair Roton
EBM-Papst
NMB
Panasonic
Sunon
MANUFACTURER
______________________________________________________________________________________
TOP VIEW
PGND
AGND
VFAN
ADD1
DXN
DXP
FAN
V
CC
1
2
6
3
4
5
7
8
All DC brushless models can be
ordered with optional tachometer
output.
Tachometer output optional on
some models.
All DC brushless models can be
ordered with optional tachometer
output.
Panaflo and flat unidirectional
miniature fans can be ordered with
tachometer output.
Tachometer output optional on
some models.
MAX6660
QSOP
Pin Configuration
FAN MODEL OPTION
16
15
14
13
12
11
10
9
TACH IN
STBY
SMBCLK
GAIN
SMBDATA
ALERT
ADDO
OVERT
Brushless DC fans increase reliability by replacing
mechanical commutation with electronic commutation.
By lowering the voltage across the fan to reduce its
speed, the MAX6660 is also lowering the supply volt-
age for the electronic commutation and tachometer
electronics. If the voltage supplied to the fan is lowered
too far, the internal electronics may no longer function
properly. Some of the following symptoms are possible:
•
•
•
•
TRANSISTOR COUNT: 22,142
PROCESS: BiCMOS
The fan may stop spinning.
The tachometer output may stop generating a signal.
The tachometer output may generate more than two
pulses per revolution.
The problems that occur and the supply voltages at
which they occur depend on which fan is used. As
a rule of thumb, 12V fans can be expected to expe-
rience problems somewhere around 1/4 and 1/2
their rated speed.
Low-Speed Operation
Chip Information